Pumps



2, 1968 F. G. FREEMAN 3,361,077

PUMP S Filed June :21, 1965 Z7 Z8 70 W I /01 29 29 2 /7 2o H) '24 r r 2'5 /:3

'29 2/ f SE20 /7 United States Patent M 3,361,077 PUMPS Frank George Freeman, Soiihuil, England, assignor to Joseph Lucas (industries) Limited, Birmingham, En land, a British company Filed June 21, 1965, Ser. No. 465,271 Claims priority, appiieation Great Britain, July 9, 1964, 28,311/64 1 (Iiaim. (Cl. 103-173) This invention relates to pumps of the kind intended for pumping corrosive liquids.

The pumping of corrosive liquids, poses certain prob lems of lubrication of moving parts of a pump, these problems being particularly acute Where the corrosive liquid reacts violently with a conventional lubricant, such as in the case of hydrogen peroxide and lubricating oils.

The object of the present invention is to provide a pump in which these problems are overcome or reduced.

According to the present invention, a pump comprises, in combination, a body part defining two separate chambers, the body part having a plurality of bores piercing a wall dividing the two chambers, the body part also defining an inlet and an outlet, said inlet and outlet being in communication with one of said chambers, a plurality of plungers occupying the bores respectively, a rotor disposed in the other chamber, said rotor having a cam surface engageable by the plungers, so that the plungers are reciprocated in the bores to pump liquid in said one chamber, the body also defining two separate drain galleries, one adjacent to said one chamber and being for liquid to be pumped, and the other being adjacent to the other chamber and being for lubricant in said other chamber, said galleries communicating with the bores in the body part, and sealing means disposed between the plungers and bores respectively, said sealing means being disposed on opposite sides of each gallery respectively.

The invention will now be described with reference to the accompanying drawing, the single figure of which is a cross-sectional side elevation view of a pump constructed in accordance with the invention.

In this example there is provided a pump, particularly for use in pumping a corrosive liquid, such as hydrogen peroxide.

The pump comprises a hollow body part defining two separate chambers 11, 12, with one of which an inlet 13 and an outlet 14, for liquid to be pumped, communicate. The outlet 14, however, includes a plurality of nonreturn valves 15, one disposed in each of a plurality of cylinders 16 which are respectively in axial alignment with a plurality of bores 17 piercing a wall 18 in the body part 11) dividing the two chambers 11, 12. The cylinders 16 all communicate through their respective non-return valves 15, with a common gallery 19 opening into the outlet 14.

In the bores 17 are respective plungers 20, which are loaded by springs 21 into engagement with an inclined cam surface on a rotor 22 which also has an integral driving shaft 23, the rotor being disposed in the chamber 12 and the shaft 23 being supported in bearings 24. The rotor 22 bears against thrust bearings 25 on a closure member 26 at the end of the pump body part 10 remote from the inlet 13 and outlet 14. The arrangement is such that as the rotor 22 rotates, the plungers 21) are reciprocated in their respective bores 17 and enter and leave the cylinders is in turn, to pump liquid which enters when the plungers 20 are out of the cylinders 16 and which is pumped out through the non-return valves respectively, as the plungers move into the cylinders 16.

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It is necessary to provide lubricant in the chamber 12 containing the rotor 22, for lubricating the bearings 24, 25 and the cam surface but it is most important that the lubricant does not mix with the liquid to be pumped and to this end there are provided two separate drain galleries 27, 2% one of which (.27) is for liquid to be pumped, and the other of which (28) is for lubricant, the galleries being side-by-side the body part 1d and adjacent to the respective chambers 11 and 12. The drain galleries 27, 28 are in communication with the bores 1'7, and sealing means in the form of sealing rings 29 in respective grooves in the body part 10 are provided between each bore 1'7 and plunger 2%, on opposite sides of the drain galleries 27, 28 respectively. There are three such sealing rings 29 in each bore, one between each chamber and associated drain gallery and one between the two drain galleries. Each sealing ring 29 comprises a resilient O ring acting against a short cylindrical sleeve formed from a material such as fluon, though it is to be understood that other kinds of seals may be employed.

Having thus described my invention what I claim as new and desire to secure by Letters Fatent is:

1. A pump comprising, in combination, a body part, a wall within the body part dividing the interior thereof in two separate chambers, there being a plurality of bores piercing said wall, the body part also having an inlet and an outlet communicating with one of said chambers, a plurality of plungers occupying the bores respectively, a rotor disposed in the other chamber, said rotor having a cam surface engageable by the plungers, so that as the rotor rotates the plungers are reciprocated to pump liquid from said inlet to the outlet of said one chamber, said other chamber containing a liquid, which if mixed, even in smail amounts, with the liquid being pumped would produce a violent reaction, the said body part also having spaces therein defining two completely isolated leakage collecting drain galleries, each provided adjacent to said one chamber and being for liquid to be pumped, and the other being provided adjacent to said other chamber and being for liquid in said other chamber, said galleries being being formed as annular grooves separated by a land therebetween, extending from the outer circumference of said wall radially inwardly beyond said bores in the wall, means communicating with the isolated drain galleries for transporting away from said pump, in. completely separated condition, any leakage that finds its way into said isolated drain galleries, thereby preventing a violent reaction of a mixture of leakage liquids, and sealing means disposed between the plungers and the bores respectively, said sealing means being disposed in said land between said galleries and also at opposite sides of each gallery respectively.

References Cited UNITED STATES PATENTS 980,282 1/1911 Jungren 27759 X 2,230,501 2/1941 MacArthur 27759 X 2,232,976 2/1941 Schmied 103-l73 2,588,481 3/1952 Chandler 103-173 2,829,489 4/1958 Meyer 6035.6 3,018,737 1/1962 Cook et al. 103-173 3,209,701 10/1965 Phinney 103-173 3,212,448 10/1965 Johnston M 103-173 DONLEY J. STOCKiNG, Primary Examiner.

MARK M. NEWMAN, WILLIAM L. FREEH,

Examiners. R. M. VARGO, Assistant Examiner. 

1. A PUMP COMPRISING, IN COMBINATION, A BODY PART, A WALL WITHIN THE BODY PART DIVIDING THE INTERIOR THEREOF IN TWO SEPARATE CHAMBERS, THERE BEING A PLURALITY OF BORES PIERCING SAID WALL, THE BODY PARTS ALSO HAVING AN INLET AND AN OUTLET COMMUNICATING WITH ONE OF SAID CHAMBERS, A PLURALITY OF PLUNGERS OCCUPYING THE BORES RESPECTIVELY, A ROTOR DISPOSED IN THE OTHER CHAMBER, SAID ROTOR HAVING A CAM SURFACE ENGAGEABLE BY THE PLUNGERS, SO THAT AS THE ROTOR ROTATES THE PLUNGERS ARE RECIPROCATED TO PUMP LIQUID FROM SAID INLET TO THE OUTLET OF SAID ONE CHAMBER, SAID OTHER CHAMBER CONTAINING A LIQUID, WHICH IF MIXED, EVEN IN SMALL AMOUNTS, WITH THE LIQUID BEING PUMPED WOULD PRODUCE A VIOLET REACTION, THE SAID BODY PART ALSO HAVING SPACES THEREIN DEFINING TWO COMPLETELY ISOLATED LEAKAGE COLLECTING DRAIN GALLERIES, EACH PROVIDED ADJACENT TO SAID ONE CHAMBER AND BEING FOR LIQUID TO BE PUMPED, AND THE OTHER BEING PROVIDED ADJACENT TO SAID OTHER CHAMBER AND BEING FOR LIQUID IN SAID OTHER CHAMBER, SAID GALLERIES BEING BEING FORMED AS ANNULAR GROOVES SEPARATED BY A LAND THEREBETWEEN, EXTENDING FROM THE OUTER CIRCUMFERENCE OF SAID WALL RADIALLY INWARDLY BEYOND SAID BORES IN THE WALL, MEANS COMMUNICATING WITH THE ISOLATED DRAIN GALLERIES FOR TRANSPORTING AWAY FROM SAID PUMP, IN COMPLETELY SEPATRATED CONDITION, ANY LEAKAGE THAT FINDS ITS WAY INTO SAID ISOLATED DRAIN GALLERIES, THEREBY PREVENTING A VIOLENT REACTION OF A MIXTURE OF LEAKAGE LIQUIDS, AND SEALING MEANS DISPOSED BETWEEN THE PLUNGERS AND THE BORES RESPECTIVELY, SAID SEALING MEANS BEING DISPOSED IN SAID LAND BETWEEN SAID GALLERIES AND ALSO AT OPPOSITE SIDES OF EACH GALLERY RESPECTIVELY. 